1、Designation: C 1414 01 (Reapproved 2007)Standard Practice forThe Separation of Americium from Plutonium by IonExchange1This standard is issued under the fixed designation C 1414; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the
2、year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice describes the use of an ion exchangetechnique to separate plutonium from solutions containing l
3、owconcentrations of americium prior to measurement ofthe241Am by gamma counting.1.2 This practice covers the removal of plutonium, but notall the other radioactive isotopes that may interfere in thedetermination of241Am.1.3 This practice can be used when241Am is to be deter-mined in samples in which
4、 the plutonium is in the form ofmetal, oxide, or other solid provided that the solid is appropri-ately sampled and dissolved (See Test Methods C 758, C 759,and C 1168).1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of
5、 the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C 758 Test Methods for Chemical, Mass Spectrometric,Spectrochemical, Nuclear, and Radiochemical Analysis
6、 ofNuclear-Grade Plutonium MetalC 759 Test Methods for Chemical, Mass Spectrometric,Spectrochemical, Nuclear, and Radiochemical Analysis ofNuclear-Grade Plutonium Nitrate SolutionsC 1168 Practice for Preparation and Dissolution of Pluto-nium Materials for AnalysisC 1268 Test Method for Quantitative
7、Determination ofAmericium 241 in Plutonium by Gamma-Ray Spectrom-etryD 1193 Specification for Reagent Water3. Summary of Practice3.1 Plutonium is adsorbed from a nitric acid (HNO3) solu-tion (8 M) onto an anion exchange resin. Under these condi-tions, a negligible amount of americium is adsorbed ont
8、o theresin and may be determined by gamma counting of the eluateusing Test Method C 1268.4. Significance and Use4.1 This practice is applicable when small amountsof241Am are present in plutonium samples (see Test MethodsC 758 and C 759). An example is the determination of241Amin a238Pu sample. The h
9、igh specific activity of238Pu presentsa safety hazard that precludes its presence in a countingfacility. Therefore, it is necessary to remove the238Pu prior tothe determination of241Am.4.2 When a plutonium solution contains fission or activationproducts, this practice does not separate all radionucl
10、ides thatinterfere in the determination of241Am, such as the rare earths.5. Interferences5.1 The presence of other gamma-ray emitting radionu-clides similar in energy to241Am or that interfere with gammacounting make the determination of241Am less accurate. Most+4 valence actinides are adsorbed on t
11、he resin. The distributioncoefficient for Am on this resin in nitric acid is less than 1,indicating insignificant adsorption. Therefore, this practice willseparate many elements that might interfere with gammacounting of241Am.5.1.1 The elements thorium, neptunium (IV), gold, plati-num, iridium, and
12、palladium are not quantitatively separatedfrom plutonium by this procedure.6. Apparatus6.1 Anion exchange resin column (100-200 mesh), contain-ing quaternary ammonium functional groups (basic resin-chloride ionic form).36.2 Bottles, polyethylene, 30 mL.6.3 Sample beaker, 30 mL, borosilicate glass.1T
13、his practice is under the jurisdiction of ASTM Committee C26 on NuclearFuel Cycle and is the direct responsibility of Subcommittee C26.05 on Methods ofTest.Current edition approved Feb. 1, 2007. Published March 2007. Originallyapproved in 1999. Last previous edition approved in 2001 as C 141401.2For
14、 referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Prefilled columns packed with AG 1-X8, available from Bio-Rad, R
15、ichmond,CA, have been found to be acceptable.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6.4 Hot plate.7. Reagents7.1 Purity of ReagentsReagent grade chemicals should beused in all tests. Unless otherwise indicated, it is intende
16、d thatall reagents conform to the specifications of the Committee onAnalytical Reagents of the American Chemical Society, wheresuch specifications are available.4Other grades may be used,provided that the reagent is first demonstrated to be ofsufficiently high purity to permit its use without lessen
17、ing theaccuracy of the determination.7.2 Purity of Water Unless otherwise indicated, refer-ences to water shall be understood to mean distilled ordeionized water (Specification D 1193).7.3 Nitric acid (HNO3), concentrated (sp gr 1.42).7.4 Hydrochloric acid (HCl), concentrated (sp gr 1.19).7.5 Nitric
18、 acid, 0.1 M. Add 6 mL of concentrated HNO3(spgr 1.42) to 950 mL of water and dilute to 1 L.7.6 Nitric acid 8 M. Add 500 mL of concentrated HNO3(spgr 1.42) to 400 mL of water and dilute to 1 L.7.7 Hydrofluoric acid (HF), concentrated (sp. gr. 1.18).7.8 Strip solution, 0.1 M HCl/0.01 M HF. Add 8.3 mL
19、 ofconcentrated HCl (sp gr. 1.19) and 0.4 mL (6 to 7 drops) ofconcentrated HF to 950 mL of water and dilute to 1 L.8. Procedure8.1 Prepare a plutonium solution by following the procedurein Practice C 1168 or by using another suitable dissolutiontechnique. Transfer an aliquot of the plutonium solutio
20、n to a 30mL beaker. The amount of plutonium must be less than theadsorption capacity of the ion exchange resin. A maximum of50 mg of plutonium is suggested for the prefilled columns.8.2 Evaporate the sample to dryness on a hot plate. Add 3-4mL of 8 M HNO3and take to dryness again. Cool the sampleto
21、room temperature and repeat the dissolution and evaporationonce more before proceeding to 8.3.8.3 Condition a prefilled anion exchange column by adding3-5 mL of 8 M HNO3and allow to drain. Discard the eluant.8.4 Position a clean 1 oz polyethylene bottle beneath thecolumn to collect the effluent. Dis
22、solve the plutonium samplein beaker containing 3-4 mL of 8 M HNO3. Transfer contentsof the beaker to the preconditioned ion exchange column.8.5 Allow solution to drain into the bottle. Rinse beakerwith 3-4 mL of 8 M HNO3. Transfer the rinse from the beakerto a column and allow the solution to drain
23、into a bottle. Repeatthis process twice more, allowing column to drain betweenadditions before proceeding to 8.6.8.6 Add 10 mL of 8 M HNO3directly to the column for thefinal rinse and allow to drain. Remove the bottle and addsufficient 8 M HNO3to make a total volume equal to 25 6 2mL.8.7 Survey the
24、bottle for external contamination.8.7.1 If bottle exterior is found to be contaminated, clean toacceptable levels of activity and transfer to a counting facility.8.7.2 If no contamination is found, transfer the bottle to acounting facility and determine the activity of gamma countingaccording to Tes
25、t Method C 1268.8.8 Strip the plutonium from the column with three 5 mLaliquots of 0.1 M HNO3or 1.0 M HCl/0.01 M HF.5Discard thecolumn and place the plutonium in the appropriate wastestream, or keep for further analysis.9. Keywords9.1 americium; gamma counting; ion exchange; plutoniumsolutionsASTM I
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29、Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at
30、610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).4Reagent Chemicals, American Chemical Society Specifications , AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical soci
31、ety, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmaceutical Convention, Inc. (USPC), Rockville,MD.50.1 M HCl/0.01 M HF is used when a more complete removal of plutoniumfrom the ion exchange resin is desired.C 1414 01 (2007)2
